text: """scons.Node.Python
  
  Python nodes.
  
  """
  
  #
  # Copyright (c) 2001 - 2015 The SCons Foundation
  #
  # Permission is hereby granted, free of charge, to any person obtaining
  # a copy of this software and associated documentation files (the
  # "Software"), to deal in the Software without restriction, including
  # without limitation the rights to use, copy, modify, merge, publish,
  # distribute, sublicense, and/or sell copies of the Software, and to
  # permit persons to whom the Software is furnished to do so, subject to
  # the following conditions:
  #
  # The above copyright notice and this permission notice shall be included
  # in all copies or substantial portions of the Software.
  #
  # THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY
  # KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE
  # WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  # NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  # LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  # OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  # WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  #
  
  __revision__ = "src/engine/SCons/Node/Python.py rel_2.3.5:3347:d31d5a4e74b6 2015/07/31 14:36:10 bdbaddog"
  
  import SCons.Node
  
  class ValueNodeInfo(SCons.Node.NodeInfoBase):
      current_version_id = 1
  
      field_list = ['csig']
  
      def str_to_node(self, s):
          return Value(s)
  
  class ValueBuildInfo(SCons.Node.BuildInfoBase):
      current_version_id = 1
  
  class Value(SCons.Node.Node):
      """A class for Python variables, typically passed on the command line 
      or generated by a script, but not from a file or some other source.
      """
  
      NodeInfo = ValueNodeInfo
      BuildInfo = ValueBuildInfo
  
      def __init__(self, value, built_value=None):
          SCons.Node.Node.__init__(self)
          self.value = value
          if built_value is not None:
              self.built_value = built_value
  
      def str_for_display(self):
          return repr(self.value)
  
      def __str__(self):
          return str(self.value)
  
      def make_ready(self):
          self.get_csig()
  
      def build(self, **kw):
          if not hasattr(self, 'built_value'):
              SCons.Node.Node.build(self, **kw)
  
      is_up_to_date = SCons.Node.Node.children_are_up_to_date
  
      def is_under(self, dir):
          # Make Value nodes get built regardless of 
          # what directory scons was run from. Value nodes
          # are outside the filesystem:
          return 1
  
      def write(self, built_value):
          """Set the value of the node."""
          self.built_value = built_value
  
      def read(self):
          """Return the value. If necessary, the value is built."""
          self.build()
          if not hasattr(self, 'built_value'):
              self.built_value = self.value
          return self.built_value
  
      def get_text_contents(self):
          """By the assumption that the node.built_value is a
          deterministic product of the sources, the contents of a Value
          are the concatenation of all the contents of its sources.  As
          the value need not be built when get_contents() is called, we
          cannot use the actual node.built_value."""
          ###TODO: something reasonable about universal newlines
          contents = str(self.value)
          for kid in self.children(None):
              contents = contents + kid.get_contents()
          return contents
  
      get_contents = get_text_contents    ###TODO should return 'bytes' value
  
      def changed_since_last_build(self, target, prev_ni):
          cur_csig = self.get_csig()
          try:
              return cur_csig != prev_ni.csig
          except AttributeError:
              return 1
  
      def get_csig(self, calc=None):
          """Because we're a Python value node and don't have a real
          timestamp, we get to ignore the calculator and just use the
          value contents."""
          try:
              return self.ninfo.csig
          except AttributeError:
              pass
          contents = self.get_contents()
          self.get_ninfo().csig = contents
          return contents
  
  # Local Variables:
  # tab-width:4
  # indent-tabs-mode:nil
  # End:
  # vim: set expandtab tabstop=4 shiftwidth=4:
  